Atomic layer deposition of tantalum-containing materials using the tantalum precursor TAIMATA

ABSTRACT

In one example of the invention, a method for depositing a tantalum-containing material on a substrate in a process chamber is provided which includes exposing the substrate to a tantalum precursor that contains TAIMATA and to at least one secondary precursor to deposit a tantalum-containing material during an atomic layer deposition (ALD) process. The ALD process is repeated until the tantalum-containing material is deposited having a predetermined thickness. Usually, the TAIMATA is preheated prior to pulsing the tantalum precursor into the process chamber. Subsequently, a metal layer, such as tungsten or copper, may be deposited on the tantalum-containing material. The tantalum-containing material may contain tantalum, tantalum nitride, tantalum silicon nitride, tantalum boron nitride, tantalum phosphorous nitride, or tantalum oxynitride. The tantalum-containing material may be deposited as a barrier or adhesion layer within a via or as a gate electrode material within a source/drain device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit of U.S. Provisional Patent ApplicationNo. 60/589,402, filed Jul. 20, 2004 and U.S. Provisional PatentApplication No. 60/590,216, filed Jul. 21, 2004, both entitled “AtomicLayer Deposition of Tantalum-containing Materials Using the TantalumPrecursor TAIMATA,” which are both herein incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to electronic device processing. Moreparticularly, this invention relates to improvements in the process ofdepositing tantalum-containing layers on substrates using sequentialdeposition techniques.

2. Description of the Related Art

The electronic device industry and the semiconductor industry continueto strive for larger production yields while increasing the uniformityof layers deposited on substrates having increasingly larger surfaceareas. These same factors in combination with new materials also providehigher integration of circuits per unit area on the substrate. Ascircuit integration increases, the need for greater uniformity andprocess control regarding layer characteristics rises. Formation oftantalum-containing layers, such as tantalum, tantalum nitride andtantalum silicon nitride, in multi-level integrated circuits poses manychallenges to process control, particularly with respect to contactformation.

Contacts are formed by depositing conductive interconnect material in anopening (e.g., via) on the surface of insulating material disposedbetween two spaced-apart conductive layers. Copper is the most popularconductive interconnect material, but suffers from diffusion intoneighboring layers, such as dielectric layers. The resulting andundesirable presence of copper causes dielectric layers to becomeconductive and ultimate device failure. Therefore, barrier materials areused to control copper diffusion.

Barrier layers formed from sputtered tantalum and reactive sputteredtantalum nitride have demonstrated properties suitable for use tocontrol copper diffusion. Exemplary properties include highconductivity, high thermal stability and resistance to diffusion offoreign atoms. Both physical vapor deposition (PVD) and atomic layerdeposition (ALD) processes are used to deposit tantalum or tantalumnitride in features of small size (e.g., about 90 nm wide) and highaspect ratios of about 5:1. However, it is believed that PVD processesmay have reached a limit at this size and aspect ratio, while ALDprocesses are anticipated to be used in the next generation technologyof 45 nm wide features having aspect ratios of about 10:1. Also, ALDprocesses more easily deposit tantalum-containing films on featurescontaining undercuts than does PVD processes.

Attempts have been made to use traditional tantalum precursors found inexisting chemical vapor deposition (CVD) or ALD processes to deposittantalum-containing films. Examples of tantalum precursors may includetantalum chloride (TaCl₅) and various metal-organic sources, such aspentakis(diethylamido)tantalum (PDEAT), pentakis(dimethylamido)tantalum(PDMAT), tertbutylimidotris(diethylamido)tantalum (TBTDEAT) andtertbutylimidotris(dimethylamido)tantalum (TBTDMAT). However,traditional tantalum precursors may suffer drawbacks during depositionprocesses. Formation of tantalum-containing films from processes usingTaCl₅ as a precursor may require as many as three treatment cycles usingvarious radial based chemistries (e.g., atomic hydrogen or atomicnitrogen) to form metallic tantalum or tantalum nitride. Processes usingTaCl₅ may also suffer from chlorine contamination within thetantalum-containing layer. While metal-organic sources of tantalumproduce tantalum-containing materials with no chlorine contamination,the deposited materials may suffer with the undesirable characteristicof high carbon content.

Therefore, there is a need for a process to deposit tantalum-containingmaterials into high aspect ration features having a high level ofsurface uniformity and a low concentration of contaminant.

SUMMARY OF THE INVENTION

In one embodiment, a method for forming a tantalum barrier layer on asubstrate disposed in a process chamber is provided which includesheating a tantalum precursor containing TAIMATA to a predeterminedtemperature to form a tantalum-containing gas and flowing thetantalum-containing gas into the process chamber. Thetantalum-containing gas is adsorbed on the substrate to form atantalum-containing layer. The method further includes purging theprocess chamber with a purge gas, flowing at least one secondaryelement-containing gas into the process chamber, reacting the at leastone secondary element-containing gas with the tantalum-containing layerto form the tantalum barrier layer and purging the process chamber withthe purge gas. The TAIMATA may be heated to the predeterminedtemperature in a range from about 50° C. to about 80° C.

In another example, a method for forming a device by forming atantalum-containing material on a substrate disposed in a processingchamber is provided which includes forming a tantalum-containing gas byheating a liquid TAIMATA precursor in a vaporizer with a carrier gas toa predetermined temperature. The method further includes exposing thesubstrate to an atomic layer deposition process comprising a pulse of atantalum-containing gas, a pulse of the nitrogen-containing gas and apulse of a silicon-containing gas and forming the tantalum-containingmaterial to a predetermined thickness by repeating the atomic layerdeposition process.

In another example, a method for depositing a tantalum-containingmaterial on a substrate in a process chamber is provided which includesexposing the substrate sequentially to a pulse of a tantalum-containinggas containing TAIMATA and to a pulse of a process gas containing atleast one secondary precursor to deposit a tantalum-containing film onthe substrate. The exposing step is repeated until thetantalum-containing film is at a predetermined thickness andsubsequently, a metal layer is deposited on the tantalum-containingfilm.

In another embodiment, a method for depositing a tantalum-containinggate material on a substrate in a process chamber is provide whichincludes exposing the substrate to an ALD process cycle that includes apulse of a tantalum-containing gas that contains TAIMATA, a pulse of anitrogen precursor and a pulse of a third precursor to form atantalum-containing material. The third precursor may include a siliconprecursor, a boron precursor, a phosphorous precursor or combinationsthereof. The ALD process cycle is repeated until the tantalum-containingmaterial is at a predetermined thickness.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the inventioncan be understood in detail, a more particular description of theinvention, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of the invention and are therefore not to beconsidered limiting of its scope, for the invention may admit to otherequally effective embodiments.

FIG. 1 is a detailed cross-sectional view of a substrate beforedeposition of a barrier layer in accordance with one embodimentdescribed herein;

FIG. 2 is a detailed cross-sectional view of a substrate shown above inFIG. 1 after deposition of a barrier layer and a metal contact inaccordance with one embodiment described herein;

FIG. 3 is flow diagram showing a method of depositing atantalum-containing layer in accordance with one embodiment describedherein;

FIG. 4 is flow diagram showing a method of depositing atantalum-containing layer in accordance with another embodimentdescribed herein; and

FIG. 5 is a cross-sectional view of a substrate containing atantalum-containing gate electrode in accordance with one embodimentdescribed herein.

DETAILED DESCRIPTION

Embodiments of the invention include atomic layer deposition (ALD)processes to deposit a tantalum-containing material onto a substratesurface. The ALD processes include sequentially exposing the substratesurface to a tantalum precursor and at least a second compound, such asa nitrogen precursor and/or a silicon precursor. The process generallyemploys the tantalum precursortertiaryamylimido-tris(dimethylamido)tantalum (TAIMATA). The depositedtantalum-containing material may include tantalum, tantalum nitride,tantalum silicon nitride, tantalum boron nitride, tantalum phosphorusnitride and tantalum oxynitride.

Referring to FIG. 1 a substrate 10 has an exemplary structure upon whicha tantalum-containing layer can be deposited is shown. Substrate 10includes a wafer 12 that may have one or more layers, shown as layer 14,disposed thereon. Wafer 12 may be formed from a material suitable forsemiconductor processing, such as silicon or silicon. Layer 14 may beformed from any suitable material, including dielectric or conductivematerials. Preferably, layer 14 is a dielectric material such as asilicon-containing material. Layer 14 may also include a void 16exposing a region 18 of wafer 12.

Referring to FIG. 2, formed on layer 14 and within region 18 is abarrier layer 20 containing a tantalum-containing material deposited byprocesses described herein. In one example, barrier layer 20 is formedfrom tantalum nitride or tantalum silicon nitride by sequentiallyexposing substrate 10 to a tantalum precursor and at least a secondelemental precursor, such as a nitrogen precursor and/or siliconprecursor. Although not required, barrier layer 20 may containmonolayers of multiple compounds, such as tantalum nitride and tantalummetal. Tantalum nitride barrier layer 20 conforms to the profile of void16 so as to cover region 18 and layer 14. A contact 22 is fabricated byformation of a metal layer 24 deposited on barrier layer 20, fillingvoid 16. Metal layer 24 may be formed using standard techniques (e.g.,ALD, PVD, CVD, electroless plating, electroplating or combinationsthereof) and include seed formation and/or fill. Metal layer 24 is aconductive metal that includes copper, tungsten, aluminum, tantalum,titanium, ruthenium, silver, alloys thereof or combinations thereof.Preferably, metal layer 24 contains copper or a copper-containing alloy.

In one example, barrier layer 20 serves as a seed layer to promote theformation of metal layer 24 using, for example, electroplating or ALDtechniques. Important characteristics that barrier layer 20 shoulddemonstrate include good step coverage, thickness uniformity, highelectrical conductivity and ability to prohibit copper diffusion.Barrier layer 20 is deposited employing sequential techniques, such asatomic layer deposition further described herein.

One example of forming barrier layer 20 employing sequential depositiontechniques includes exposing substrate 10 to a tantalum-containing gasformed by vaporizing the liquid precursor TAIMATA. “TAIMATA” is usedherein to describe tertiaryamylimido-tris(dimethylamido)tantalum withthe chemical formula (^(t)AmyIN)Ta(NMe₂)₃, wherein ^(t)Amyl is thetertiaryamyl group (C₅H₁₁—or CH₃CH₂C(CH₃)₂—). A tantalum-containing gasmay be formed by heating a liquid TAIMATA precursor in a vaporizer, abubbler or an ampoule to a temperature of at least 30° C., preferably toa temperature in a range from about 50° C. to about 80° C. A carrier gasis flown across or bubbled through the heated TAIMATA to form atantalum-containing gas.

Substrate 10 is placed in to a process chamber and heated to atemperature in a range from about 200° C. to about 500° C., preferablyfrom about 250° C. to about 400° C., and more preferably from about 330°C. to about 360° C. The process chamber has a controlled environmentthat is pressurized in a range from about 1 mTorr to about 100 Torr,preferably from about 1 Torr to about 10 Torr, and more preferably fromabout 2 Torr to about 5 Torr. Substrate 10 is exposed to a process gasthat includes the tantalum-containing gas and a carrier gas. Herein, thecarrier gas and/or the purge gas may be Ar, He, N₂, H₂, forming gas andcombinations thereof. A tantalum-containing layer is formed on substrate10. It is believed that the tantalum-containing layer has a surface ofligands comprising amido (—NMe₂) and imido (═N^(t)Amyl).

In one example, the tantalum-containing layer is exposed to anotherprocess gas that includes a nitrogen-containing gas and a carrier gas todeposit the tantalum-containing layer forming a barrier layer 20 oftantalum nitride. In this example, the nitrogen-containing gas maycomprise ammonia and a carrier gas. It is believed that the amido andimido ligands in the exposed surface of the tantalum-containing layerreact with the ammonia to form byproducts that include radicals (e.g.,NH₂, NMe₂, N^(t)Amyl, HN^(t)Amyl or ^(t)Amyl), pentene, amines (e.g.,HNMe₂ or H₂N^(t)Amyl), (Me₂N)₂ and H₂ among others. In this manner, asurface containing a layer of tantalum nitride is formed on substrate10.

Barrier layer 20 is a tantalum-containing material. In a preferredembodiment, the tantalum-containing material is tantalum nitride ortantalum silicon nitride. An example of the deposition process may formtantalum nitride with the chemical formula TaN_(x), where x is in arange from about 0.4 to about 2.0. Tantalum nitride is often derivedwith empirical formulas that include TaN, Ta₃N₅ Ta₂N or Ta₆N_(2.57).Tantalum-containing materials are deposited as amorphous or crystallinematerials. The ALD process provides stoichiometric control during thedeposition of tantalum-containing materials. The stoichiometry may bealtered by various procedures following the deposition process, such aswhen Ta₃N₅ is thermally annealed to form TaN. The ratio of theprecursors may be altered during deposition to control the stoichiometryof the tantalum-containing compounds materials.

In another example of the deposition process, tantalum silicon nitridemay be formed with the chemical formula TaSi_(y)N_(x), where x is in arange from about 0.4 to about 2.0 and y is in a range from about 0.1 toabout 1.0. In other examples, the tantalum-containing compounds formedby deposition processes described herein include tantalum, tantalumphosphorous nitride, tantalum boron nitride, tantalum silicide, tantalumoxide, tantalum oxynitride, tantalum silicate, tantalum boride, tantalumphosphide or derivatives thereof.

An important precursor characteristic is to have a favorable vaporpressure. Deposition precursors may have gas, liquid or solid states atambient temperature and pressure. However, within the ALD chamber,precursors are volatilized as gas or plasma. Precursors are usuallyheated prior to delivery into the process chamber.

Although TAIMATA is the preferred tantalum-containing precursor, othertantalum precursors that may be heated to form tantalum-containinggases. Tantalum precursors may contain ligands such as alkylamidos,alkylimidos, cyclopentadienyls, halides, alkyls, alkoxides andcombinations thereof. Alkylamido tantalum compounds used as tantalumprecursors include (RR′N)₅Ta, where R or R′ are independently hydrogen,methyl, ethyl, propyl or butyl. Alkylimido tantalum compounds used astantalum precursors include (RN)(R′R″N)₃Ta, where R, R′ or R″ areindependently hydrogen, methyl, ethyl, propyl, butyl or pentyl (amyl).Specific tantalum precursors may include (^(t)AmyIN)Ta(NMe₂)₃,(^(t)AmyIN)Ta(NEt₂)₃, (^(t)AmyIN)Ta(NMeEt)₃, (^(t)BuN)Ta(NMe₂)₃,(^(t)BuN)Ta(NEt₂)₃, (^(t)BuN)Ta(NMeEt)₃, (Et₂N)₅Ta, (Me₂N)₅Ta,(EtMeN)₅Ta, (Me₅C₅)TaCl₄, (acac)(EtO)₄Ta, Br₅Ta, Cl₅ Ta, I₅Ta, F₅Ta,(NO₃)₅Ta, (^(t)BuO)₅Ta, (^(i)PrO)₅Ta, (EtO)₅Ta and (MeO)₅Ta. Preferably,the tantalum precursor is an amylimido compound, such as(^(t)AmyIN)Ta(NMe₂)₃, (^(t)AmyIN)Ta(NEt₂)₃ or (^(t)AmyIN)Ta(NMeEt)₃.

Nitrogen-containing compounds or nitrogen precursors may be used todeposit tantalum-containing materials, such as tantalum nitride,tantalum boron nitride, tantalum silicon nitride, tantalum phosphorousnitride or tantalum oxynitride. Nitrogen precursors include, but are notlimited to, ammonia (NH₃), hydrazine (N₂H₄), methyl hydrazine((CH₃)HN₂H₂), dimethyl hydrazine ((CH₃)₂N₂H₂), t-butylhydrazine(C₄H₉N₂H₃), phenylhydrazine (C₆H₅N₂H₃), other hydrazine derivatives,amines, a nitrogen plasma source (e.g., N₂, N₂/H₂, NH₃, or a N₂H₄plasma), 2,2′-azotertbutane ((CH₃)₆C₂N₂), organic or alkyl azides, suchas methylazide (CH₃N₃), ethylazide (C₂H₅N₃), trimethylsilylazide(Me₃SiN₃), inorganic azides (e.g., NaN₃ or Cp₂CoN₃) and other suitablenitrogen sources. Radical nitrogen compounds can be produced by heat,hot-wires and/or plasma, such as N₃, N₂, N, NH or NH₂. Preferably, thenitrogen precursor is ammonia or hydrazine.

Silicon-containing compounds or silicon precursors may be used todeposit tantalum-containing materials, such as tantalum silicon nitride,tantalum silicate or tantalum silicide. Silicon precursors includesilanes, halogenated silanes and organosilanes. Silanes include silane(SiH₄) and higher silanes with the empirical formula Si_(x)H_((2x+2)),such as disilane (Si₂H₆), trisilane (Si₃H₈), and tetrasilane (Si₄H₁₀),as well as others. Halogenated silanes include compounds with theempirical formula X′_(y)Si_(x)H_((2x+2−y)), where X′ is independently F,Cl, Br or I, such as hexachlorodisilane (Si₂Cl₆), tetrachlorosilane(SiCl₄), dichlorosilane (Cl₂SiH₂) and trichlorosilane (Cl₃SiH).Organosilanes include compounds with the empirical formulaR_(y)Si_(x)H_((2x+2−y)), where R is independently methyl, ethyl, propylor butyl, such as methylsilane ((CH₃)SiH₃), dimethylsilane ((CH₃)₂SiH₂),ethylsilane ((CH₃CH₂)SiH₃), methyldisilane ((CH₃)Si₂H₅),dimethyldisilane ((CH₃)₂Si₂H₄) and hexamethyldisilane ((CH₃)₆Si₂). Thepreferred silicon sources include silane, disilane and methylsilane.

Other reactive gases that may be used to deposit tantalum-containingmaterials include oxygen sources and reductants. A tantalum-containingmaterial, such as tantalum silicate, tantalum oxide or tantalumoxynitride may be formed with the addition of an oxygen source to theALD process. Oxygen sources or oxygen precursors include atomic-O, O₂,O₃, H₂O, H₂O₂, organic peroxides, derivatives thereof and combinationsthereof. Reducing compounds may be included in the ALD process to form atantalum-containing compound, such as metallic tantalum, tantalum boronnitride or tantalum phosphorous nitride. Reducing compounds includeborane (BH₃), diborane (B₂H₆), alkylboranes (e.g., Et₃B), phosphine(PH₃), hydrogen (H₂), derivatives thereof and combinations thereof.

“Atomic layer deposition” or “cyclical deposition” as used herein refersto the sequential introduction of two or more reactive compounds todeposit a layer of material on a substrate surface. The two, three ormore reactive compounds may alternatively be introduced into a reactionzone of a processing chamber. Usually, each reactive compound isseparated by a time delay to allow each compound to adhere and/or reacton the substrate surface. In one aspect, a first precursor or compound A(e.g., tantalum precursor) is pulsed into the reaction zone followed bya first time delay. Next, a second precursor or compound B (e.g.,nitrogen precursor) is pulsed into the reaction zone followed by asecond delay. During each time delay a purge gas, such as nitrogen, isintroduced into the processing chamber to purge the reaction zone orotherwise remove any residual reactive compound or by-products from thereaction zone. Alternatively, the purge gas may flow continuouslythroughout the deposition process so that only the purge gas flowsduring the time delay between pulses of reactive compounds. The reactivecompounds are alternatively pulsed until a desired film or filmthickness is formed on the substrate surface. In either scenario, theALD process of pulsing compound A, purge gas, pulsing compound B andpurge gas is a cycle. A cycle can start with either compound A orcompound B and continue the respective order of the cycle untilachieving a film with the desired thickness.

A “pulse” as used herein is intended to refer to a quantity of aparticular compound that is intermittently or non-continuouslyintroduced into a reaction zone of a processing chamber. The quantity ofa particular compound within each pulse may vary over time, depending onthe duration of the pulse. The duration of each pulse is variabledepending upon a number of factors such as, for example, the volumecapacity of the process chamber employed, the vacuum system coupledthereto, the size of the substrate, the pattern density on the substratesurface (e.g., aspect ratio) and the volatility/reactivity of theparticular precursor compound itself. A “half-reaction” as used hereinto refer to a precursor pulse step followed by a purge pulse step.

Embodiments of the processes described herein deposittantalum-containing materials, such as tantalum nitride or tantalumsilicon nitride, on various substrates surfaces and substrates. A“substrate surface” as used herein refers to any substrate or materialsurface formed on a substrate upon which film processing is performed.For example, a substrate surface on which processing may be performedinclude materials such as, silicon, silicon oxide, strained silicon,silicon on insulator (SOI), carbon doped silicon oxides, siliconnitride, doped silicon, germanium, gallium arsenide, glass, sapphire,and any other materials depending on the application. Carbon dopedsilicon oxides, such as SiO_(x)C_(y), can be deposited by spin-onprocesses or vapor deposition processes, for example, BLACK DIAMOND®low-k dielectric, available from Applied Materials, Inc., located inSanta Clara, California. Substrates may have various dimensions, such as200 mm or 300 mm diameter round wafers, as well as, rectangular, orsquare panes. Embodiments of the processes described herein deposittantalum-containing materials on many substrates and surfaces,especially, silicon and silicon-containing materials. Substrates onwhich embodiments of the invention may be useful include, but are notlimited to semiconductor wafers such as crystalline silicon (e.g.,Si<100> or Si<111>), glass, silicon oxide, strained silicon, silicongermanium, doped or undoped polysilicon, doped or undoped silicon waferssilicon nitride. Pretreatment of surfaces includes polishing, etching,reduction oxidation, hydroxylation, annealing, and/or baking.

FIGS. 3 and 4 illustrate a process sequence for tantalum nitrideformation using ALD process or similar cyclical deposition techniques.The TAIMATA precursor may be heated in a vaporizer, a bubbler or anampoule prior to flowing into an ALD process chamber. The TAIMATA may beheated to a temperature at least 30° C., preferably in a range fromabout 45° C. to about 90° C., more preferably from about 50° C. to about80° C., such as about 70° C. The preheated TAIMATA precursor is retainedin the carrier gas more thoroughly than if the TAIMATA precursor was atroom temperature. An exemplary substrate temperature during thedeposition process is in the range from about 200° C. to about 500° C.,preferably from about 250° C. to about 400° C., and more preferably fromabout 330° C. to about 360° C. The process chamber regional varies, buthas a similar temperature to that of the substrate temperature. Theprocess chamber has a controlled environment that is pressurized in arange from about 1 mTorr to about 100 Torr, preferably from about 1 Torrto about 10 Torr, and more preferably from about 2 Torr to about 5 Torr.In other examples, it should be understood that other temperatures andpressures may be used.

For clarity and ease of description, the method will be furtherdescribed as it relates to the deposition of a tantalum nitride barrierlayer using a cyclical deposition technique. Pulses of atantalum-containing compound, such as TAIMATA may be introduced into theprocess chamber. The tantalum precursor may be provided with the aid ofa carrier gas or purge gas, which includes, but is not limited to,helium, argon, nitrogen, hydrogen, forming gas and combinations thereof.Pulses of a nitrogen-containing compound, such as ammonia, are alsointroduced into the process chamber. A carrier gas may be used todeliver the nitrogen-containing compound. In one aspect, the flow ofpurge gas may be continuously provided by a gas sources (e.g., tank orin-house) to act as a purge gas between the pulses of thetantalum-containing compound and of the nitrogen-containing compound andto act as a carrier gas during the pulses of the tantalum-containingcompound and the nitrogen-containing compound. In other aspects, a pulseof purge gas may be provided after each pulse of the tantalum-containingcompound and each pulse the nitrogen-containing compound. Also, aconstant purge or carrier gas may be flowing through the process chamberduring each of the deposition steps or half reactions.

During process 300 in FIG. 3, a constant flow of carrier gas isadministered into the process chamber. At step 302, the chamberconditions are adjusted, such as temperature and pressure. Duringdeposition, the substrate may be maintained approximately below athermal decomposition temperature of a selected tantalum precursor, suchas TAIMATA. The tantalum nitride layer formation is described asstarting a stream of carrier gas into the process chamber and across thesubstrate in step 304. In step 306, a pulse of tantalum precursor isadministered into the process chamber. The tantalum precursor is pulsedinto the stream of carrier gas. A monolayer of a tantalum-containingcompound is adsorbed on the substrate. The remaining tantalum precursormay be removed by the flow of the purge gas and/or pull of a vacuumsystem. The carrier gas is continuously exposed to the substrate and apulse of nitrogen-containing compound is added into the carrier gasduring step 308. The nitrogen precursor, such as ammonia, reacts withthe adsorbed tantalum-containing compound to form a tantalum nitridelayer on the substrate. The remaining nitrogen precursor and anyby-products (e.g., organic compounds) may be removed by the flow of thepurge gas and/or pull of a vacuum system. At step 310, if the desiredtantalum nitride layer thickness is achieved, then the depositionprocess is ended at step 312. However, multiple cycles of step 304-310are generally repeated before achieving the desired tantalum nitridelayer thickness. In one example, TAIMATA and ammonia are sequentiallypulsed for 40 cycles to deposit a film with a thickness about 20 Å.

Alternatively for process 300, the tantalum nitride layer formation maystart with the adsorption of a monolayer of a nitrogen-containingcompound on the substrate followed by a monolayer of thetantalum-containing compound. Furthermore, in other example, a pumpevacuation alone between pulses of reactant gases and/or purge gases maybe used to prevent mixing of the reactant gases.

In one example, the substrate is maintained at an invariant temperaturerange from about 330° C. to about 360° C. and the pressure of thechamber is in a range from about 2 Torr to about 4 Torr. The substrateis exposed to a flow of nitrogen carrier gas at a rate in a range fromabout 1,000 sccm to about 3,000 sccm, preferably about 1,500 sccm. Atantalum-containing process gas is formed by flowing a carrier gasthrough the ampoule of preheated TAIMATA a rate from about 200 sccm toabout 2,000 sccm, preferably about 500 sccm. The TAIMATA is maintainedat about 70° C. A process gas containing TAIMATA is administered to thesubstrate surface for a period of time in a range from about 0.1 secondsto about 3.0 seconds, preferably from about 0.25 seconds to about 1.5seconds, and more preferably about 0.5 seconds. After the substrate isexposed to a pulse of TAIMATA, the flow of carrier gas may continue topurge for a period of time in a range from about 0.2 seconds to about5.0 seconds, preferably from about 0.25 seconds to about 1.5 seconds,and more preferably about 1.0 second. A vacuum system removes anyremaining TAIMATA during this purge step. Subsequently, a pulse of anitrogen-containing process gas containing ammonia is administered tothe substrate surface. The process gas may include thenitrogen-containing precursor in a carrier gas or may be solely thenitrogen-containing precursor. In one example, the process gas containsammonia and nitrogen. The process gas containing ammonia is delivered arate from about 1,000 sccm to about 3,000 sccm, preferably about 1,500sccm and is administered to the substrate surface for a period of timein a range from about 0.1 seconds to about 3.0 seconds, preferably fromabout 0.25 seconds to about 1.0 second, and more preferably about 0.5seconds. After the pulse of the process gas containing ammonia, the flowof carrier gas may continue for a period of time in a range from about0.2 seconds to about 5.0 seconds, preferably from about 0.25 seconds toabout 1.5 seconds, and more preferably about 1.0 second. The vacuumsystem removes any remaining nitrogen precursor and/or any by-productsformed during the reaction. The ALD cycle is repeated until apredetermined thickness of the tantalum-containing layer, such astantalum nitride, is achieved, such as in a range from about 5 Å toabout 200 Å, preferably from about 10 Å to about 30 Å, such as about 20Å for a barrier layer.

In FIG. 4, process 400 illustrates another embodiment of a depositionprocess that sequentially pulses a purge gas, a tantalum precursor, thepurge gas and a nitrogen precursor. In step 402, the chamber conditionsare adjusted, such as temperature and pressure. During deposition, thesubstrate may be maintained approximately below a thermal decompositiontemperature of a selected tantalum-containing compound, such as TAIMATA.A first pulse of purge gas is administered into the process chamber andacross the substrate during step 404. A vacuum system removes gases fromthe process chamber during steps 404 and 408. During step 406, thesubstrate is exposed to a pulse of the tantalum-containing compound. TheTAIMATA adsorbs to the substrate forming a monolayer. A second pulse ofpurge gas removes excess TAIMATA and any contaminates during step 408.During step 410, a nitrogen-containing compound is pulsed into thechamber and across the substrate. The nitrogen-containing compoundreacts with the adsorbed TAIMATA to form a tantalum-containing material,such as tantalum nitride. At step 412, if the desired tantalum nitridelayer thickness is achieved, then the deposition process is ended atstep 414. However, multiple cycles of step 404-412 are generallyrepeated before achieving the desired tantalum nitride layer thickness.In one example, TAIMATA and ammonia are sequentially pulsed for 20cycles to deposit a film with a thickness about 10 Å.

In one example, the substrate is maintained at an invariant temperaturerange from about 330° C. to about 360° C. and the pressure of thechamber is in a range from about 2 Torr to about 4 Torr. Atantalum-containing process gas is formed by flowing a nitrogen carriergas through the ampoule of preheated TAIMATA a rate from about 200 sccmto about 2,000 sccm, preferably about 500 sccm. The TAIMATA ismaintained at about 70° C. in the ampoule. A process gas containingTAIMATA is administered to the substrate surface for a period of time ina range from about 0.1 seconds to about 3.0 seconds, preferably fromabout 0.25 seconds to about 1.5 seconds, and more preferably about 0.5seconds. After the pulse of TAIMATA, a pulse of purge gas isadministered into the process chamber while the vacuum system removesgas for a period of time in a range from about 0.2 seconds to about 5.0seconds, preferably from about 0.25 seconds to about 1.5 seconds, andmore preferably about 1.0 second. Subsequently, a pulse of anitrogen-containing process gas containing ammonia is administered tothe substrate surface. The process gas may include thenitrogen-containing precursor in a carrier gas or may be solely thenitrogen-containing precursor. The process gas containing ammonia isdelivered at a rate from about 1,000 sccm to about 3,000 sccm,preferably about 1,500 sccm and is administered to the substrate surfacefor a period of time in a range from about 0.1 seconds to about 3.0seconds, preferably from about 0.25 seconds to about 1.0 second, andmore preferably about 0.5 seconds. After the pulse of the process gascontaining ammonia, a pulse of purge gas is administered into theprocess chamber while a vacuum system removes gas for a period of timein a range from about 0.2 seconds to about 5.0 seconds, preferably fromabout 0.25 seconds to about 1.5 seconds, and more preferably about 1.0second. The ALD cycle is repeated until a predetermined thickness of thetantalum-containing layer, such as tantalum nitride, is achieved, suchas in a range from about 5 Å to about 200 Å, preferably from about 10 Åto about 30 Å, such as about 20 Å.

The time duration for each pulse of tantalum-containing gas, pulse ofthe nitrogen-containing gas, and pulse of purge gas between pulses ofthe reactants are variable and depend on the volume capacity of adeposition chamber employed as well as a vacuum system coupled thereto.For example, (1) a lower chamber pressure of a gas will require a longerpulse time; (2) a lower gas flow rate will require a longer time forchamber pressure to rise and stabilize requiring a longer pulse time;and (3) a large-volume chamber will take longer to fill, longer forchamber pressure to stabilize thus requiring a longer pulse time.Similarly, time between each pulse is also variable and depends onvolume capacity of the process chamber as well as the vacuum systemcoupled thereto. In general, the time duration of a pulse of thetantalum-containing gas or the nitrogen-containing gas should be longenough for adsorption or reaction of a monolayer of the compound. In oneaspect, a pulse of a tantalum-containing gas may still be in the chamberwhen a pulse of a nitrogen-containing gas enters. In general, theduration of the purge gas and/or pump evacuation should be long enoughto prevent the pulses of the tantalum-containing gas and thenitrogen-containing gas from mixing together in the reaction zone.

In another embodiment, TAIMATA may be used as a tantalum-containingcompound to form a ternary tantalum-containing material, such astantalum silicon nitride, tantalum boron nitride, tantalum phosphorousnitride, tantalum oxynitride or tantalum silicate. A more detaileddescription of a process to form ternary or quaternary elementaltantalum-containing materials is described in commonly assigned U.S.Ser. No. 10/199,419, entitled “Cyclical Deposition of Refractory MetalSilicon Nitride,” filed Jul. 18, 2002, and issued as U.S. Pat. No.7,081,271, which is incorporated herein in its entirety by reference.Processes 300 and 400 may be modified in order to obtain ternarytantalum-containing materials. For example, a tantalum silicon nitridematerial may be formed if the substrate is exposed to a pulse of asilicon precursor as an additional step of the ALD cycle containing thepulses of TAIMATA and a nitrogen precursor. Similar, a tantalumoxynitride material may be formed if the substrate is exposed to a pulseof an oxygen precursor as an additional step of the ALD cycle containingthe pulses of TAIMATA and a nitrogen precursor. In another example, atantalum silicate material may be formed if the substrate is exposed toa pulse of TAIMATA, a pulse of a silicon precursor and a pulse of anoxygen precursor during the ALD cycle. In another example, a tantalumphosphorous nitride material may be formed if the substrate is exposedto a pulse of TAIMATA, a pulse of a nitrogen precursor and a pulse of aphosphorous precursor (e.g., phosphine) during the ALD cycle. In anotherexample, a tantalum boron nitride material may be formed if thesubstrate is exposed to a pulse of TAIMATA, a pulse of a nitrogenprecursor and a pulse of a boron precursor (e.g., diborane) during theALD cycle.

In one example of forming a tantalum silicon nitride, the substrate ismaintained at an invariant temperature range from about 330° C. to about360° C. and the pressure of the chamber is in a range from about 2 Torrto about 4 Torr. A tantalum-containing process gas is formed by flowinga carrier gas through the ampoule of preheated TAIMATA a rate from about200 sccm to about 2,000 sccm, preferably about 500 sccm. The TAIMATA ismaintained at about 70° C. A process gas containing TAIMATA isadministered to the substrate surface for a period of time in a rangefrom about 0.1 seconds to about 3.0 seconds, preferably from about 0.25seconds to about 1.5 seconds, and more preferably about 0.5 seconds.After the pulse of TAIMATA, a pulse of purge gas is administered intothe process chamber for a period of time in a range from about 0.2seconds to about 5.0 seconds, preferably from about 0.25 seconds toabout 1.5 seconds, and more preferably about 1.0 second. Subsequently, apulse of a nitrogen-containing process gas containing ammonia isadministered to the substrate surface. The process gas may include thenitrogen-containing precursor in a carrier gas or may be solely thenitrogen-containing precursor. The process gas containing ammonia isdelivered a rate from about 1,000 sccm to about 3,000 sccm, preferablyabout 1,500 sccm and is administered to the substrate surface for aperiod of time in a range from about 0.1 seconds to about 3.0 seconds,preferably from about 0.25 seconds to about 1.0 second, and morepreferably about 0.5 seconds. After the pulse of the process gascontaining ammonia, a pulse of purge gas is administered into theprocess chamber for a period of time in a range from about 0.2 secondsto about 5.0 seconds, preferably from about 0.25 seconds to about 1.5seconds, and more preferably about 1.0 second. Subsequently, a pulse ofa silicon-containing process gas containing silane is administered tothe substrate surface. The process gas may include thesilicon-containing precursor in a carrier gas or may be solely thesilicon-containing precursor. The process gas containing silane isdelivered a rate from about 100 sccm to about 1,500 sccm, preferablyabout 400 sccm and is administered to the substrate surface for a periodof time in a range from about 0.1 seconds to about 3.0 seconds,preferably from about 0.25 seconds to about 1.0 second, and morepreferably about 0.5 seconds. After the pulse of the process gascontaining silane, a pulse of purge gas is administered into the processchamber for a period of time in a range from about 0.2 seconds to about5.0 seconds, preferably from about 0.25 seconds to about 1.5 seconds,and more preferably about 1.0 second. The ALD cycle is repeated until apredetermined thickness of the tantalum-containing layer, such astantalum silicon nitride, is achieved, such as in a range from about 5 Åto about 200 Å, preferably from about 10 Å to about 50 Å, such as about30 Å for a barrier layer. In another embodiment, such as for a gateelectrode layer, the predetermined thickness may be in a range fromabout 40 Å to about 200 Å, such as about 120 Å.

In an example for forming a tantalum oxynitride, the substrate ismaintained at an invariant temperature range from about 330° C. to about360° C. and the pressure of the chamber is in a range from about 2 Torrto about 4 Torr. A tantalum-containing process gas is formed by flowinga carrier gas through the ampoule of preheated TAIMATA a rate from about200 sccm to about 2,000 sccm, preferably about 500 sccm. The TAIMATA ismaintained at about 70° C. A process gas containing TAIMATA isadministered to the substrate surface for a period of time in a rangefrom about 0.1 seconds to about 3.0 seconds, preferably from about 0.25seconds to about 1.5 seconds, and more preferably about 0.5 seconds.After the pulse of TAIMATA, a pulse of purge gas is administered intothe process chamber for a period of time in a range from about 0.2seconds to about 5.0 seconds, preferably from about 0.25 seconds toabout 1.5 seconds, and more preferably about 1.0 second. Subsequently, apulse of a nitrogen-containing process gas containing ammonia isadministered to the substrate surface. The process gas may include thenitrogen-containing precursor in a carrier gas or may be solely thenitrogen-containing precursor. The process gas containing ammonia isdelivered a rate from about 1,000 sccm to about 3,000 sccm, preferablyabout 1,500 sccm and is administered to the substrate surface for aperiod of time in a range from about 0.1 seconds to about 3.0 seconds,preferably from about 0.25 seconds to about 1.0 second, and morepreferably about 0.5 seconds. After the pulse of the process gascontaining ammonia, a pulse of purge gas is administered into theprocess chamber for a period of time in a range from about 0.2 secondsto about 5.0 seconds, preferably from about 0.25 seconds to about 1.5seconds, and more preferably about 1.0 second. Subsequently, a pulse ofan oxygen-containing process gas containing water is administered to thesubstrate surface. The process gas may include the oxygen-containingprecursor in a carrier gas or may be solely the oxygen-containingprecursor. The process gas containing water is delivered a rate fromabout 100 sccm to about 1,500 sccm, preferably about 400 sccm and isadministered to the substrate surface for a period of time in a rangefrom about 0.1 seconds to about 3.0 seconds, preferably from about 0.25seconds to about 1.0 second, and more preferably about 0.5 seconds.After the pulse of the process gas containing water, a pulse of purgegas is administered into the process chamber for a period of time in arange from about 0.2 seconds to about 5.0 seconds, preferably from about0.25 seconds to about 1.5 seconds, and more preferably about 1.0 second.The ALD cycle is repeated until a predetermined thickness of thetantalum-containing layer, such as tantalum oxynitride, is achieved,such as in a range from about 5 Å to about 200 Å, preferably from about20 Å to about 120 Å, such as about 80 Å.

In another example, a metallic tantalum layer may be formed by reducingTAIMATA with a reductant, such as hydrogen. The substrate is maintainedat an invariant temperature range from about 330° C. to about 360° C.and the pressure of the chamber is in a range from about 2 Torr to about4 Torr. A tantalum-containing process gas is formed by flowing a carriergas through the ampoule of preheated TAIMATA a rate from about 200 sccmto about 2,000 sccm, preferably about 500 sccm. The TAIMATA ismaintained at about 70° C. A process gas containing TAIMATA isadministered to the substrate surface for a period of time in a rangefrom about 0.1 seconds to about 3.0 seconds, preferably from about 0.25seconds to about 1.5 seconds, and more preferably about 0.5 seconds.After the pulse of TAIMATA, a pulse of purge gas is administered intothe process chamber for a period of time in a range from about 0.2seconds to about 5.0 seconds, preferably from about 0.25 seconds toabout 1.5 seconds, and more preferably about 1.0 second. Subsequently, apulse of hydrogen gas is administered to the substrate surface. Thehydrogen gas is delivered a rate from about 200 sccm to about 2,000sccm, preferably about 500 sccm and is administered to the substratesurface for a period of time in a range from about 0.1 seconds to about3.0 seconds, preferably from about 0.25 seconds to about 1.0 second, andmore preferably about 0.5 seconds. After the pulse of the hydrogen gas,a pulse of purge gas is administered into the process chamber for aperiod of time in a range from about 0.2 seconds to about 5.0 seconds,preferably from about 0.25 seconds to about 1.5 seconds, and morepreferably about 1.0 second. The ALD cycle is repeated until apredetermined thickness of the tantalum-containing layer, such astantalum, is achieved, such as in a range from about 5 Å to about 200 Å,preferably from about 10 Å to about 30 Å, such as about 20 Å.

In an example for forming a tantalum boron nitride, the substrate ismaintained at an invariant temperature range from about 330° C. to about360° C. and the pressure of the chamber is in a range from about 2 Torrto about 4 Torr. A tantalum-containing process gas is formed by flowinga carrier gas through the ampoule of preheated TAIMATA a rate from about200 sccm to about 2,000 sccm, preferably about 500 sccm. The TAIMATA ismaintained at about 70° C. A process gas containing TAIMATA isadministered to the substrate surface for a period of time in a rangefrom about 0.1 seconds to about 3.0 seconds, preferably from about 0.25seconds to about 1.5 seconds, and more preferably about 0.5 seconds.After the pulse of TAIMATA, a pulse of purge gas is administered intothe process chamber for a period of time in a range from about 0.2seconds to about 5.0 seconds, preferably from about 0.25 seconds toabout 1.5 seconds, and more preferably about 1.0 second. Subsequently, apulse of a nitrogen-containing process gas containing ammonia isadministered to the substrate surface. The process gas may include thenitrogen-containing precursor in a carrier gas or may be solely thenitrogen-containing precursor. The process gas containing ammonia isdelivered a rate from about 1,000 sccm to about 3,000 sccm, preferablyabout 1,500 sccm and is administered to the substrate surface for aperiod of time in a range from about 0.1 seconds to about 3.0 seconds,preferably from about 0.25 seconds to about 1.0 second, and morepreferably about 0.5 seconds. After the pulse of the process gascontaining ammonia, a pulse of purge gas is administered into theprocess chamber for a period of time in a range from about 0.2 secondsto about 5.0 seconds, preferably from about 0.25 seconds to about 1.5seconds, and more preferably about 1.0 second. Subsequently, a pulse ofa boron-containing process gas containing diborane is administered tothe substrate surface. The process gas may include the boron-containingprecursor in a carrier gas or may be solely the boron-containingprecursor. The process gas containing diborane is delivered a rate fromabout 50 sccm to about 1,200 sccm, preferably about 500 sccm and isadministered to the substrate surface for a period of time in a rangefrom about 0.1 seconds to about 3.0 seconds, preferably from about 0.25seconds to about 1.0 second, and more preferably about 0.5 seconds.After the pulse of the process gas containing diborane, a pulse of purgegas is administered into the process chamber for a period of time in arange from about 0.2 seconds to about 5.0 seconds, preferably from about0.25 seconds to about 1.5 seconds, and more preferably about 1.0 second.The ALD cycle is repeated until a predetermined thickness of thetantalum-containing layer, such as tantalum boron nitride, is achieved,such as in a range from about 5 Å to about 200 Å, preferably from about40 Å to about 150 Å, such as about 100 Å.

In one embodiment as depicted in FIG. 5, tantalum-containing gate 510 isdeposited by methods described herein as a gate electrode on substrate500. Substrate 500 contains a source layer 504 a and a drain layer 504 bformed by implanting ions into substrate surface 502. The segments ofsource/drain layers 504 are bridged by the tantalum-containing gate 510formed on gate insulting layer 506 (e.g., hafnium oxide or hafniumsilicate). An off-set layer or spacer 508 (e.g., silicon nitride) isdeposited on both sides of tantalum-containing gate 510. A metal contactlayer 512 (e.g., tantalum or tungsten) is deposited on thetantalum-containing gate 510. Generally, tantalum-containing gate 510 isdeposited with a thickness in a range from about 40 Å to about 200 Å.Preferably, tantalum-containing gate 510 is deposited by an ALD processdescribed herein utilizing TAIMATA and deposited on a source/drain areaof source layer 504 a and drain layer 504 b on substrate surface 502 toform a gate electrode. Atomic layer deposition processes utilizingTAIMATA, a nitrogen precursor and third precursor provide control of theelemental ratio of tantalum-containing gate 510.

The tantalum-containing gate 510 may have a varied composition to bettercontrol the work function between source layer 504 a and drain layer 504b. Tantalum-containing gate 510 contains tantalum, nitrogen andoptionally silicon, boron, phosphorus, carbon and combinations thereof.The work function of tantalum-containing gate 510 may be adjusted to beless resistive by increasing the nitrogen and/or phosphorusconcentration relative to the tantalum concentration. In one example,tantalum-containing gate 510 contains tantalum nitride with a nitrogenconcentration in a range from about 40 atomic percent (at %) to about 70at %, preferably from about 50 at % to about 63 at %. In anotherexample, tantalum-containing gate 510 contains tantalum phosphorousnitride with a phosphorus concentration in a range from about 10 at % toabout 50 at %, preferably from about 20 at % to about 30 at %.

Alternatively, the work function of tantalum-containing gate 510 may beadjusted to be more resistive by increasing the carbon, silicon and/orboron concentration relative to the tantalum concentration. In oneexample, tantalum-containing gate 510 contains tantalum silicon nitridewith a silicon concentration in a range from about 10 at % to about 20at %. In another example, tantalum-containing gate 510 contains tantalumboron nitride with a boron concentration in a range from about 20 at %to about 60 at %, preferably from about 30 at % to about 50 at %.

A detailed description for a process chamber, such as an ALD chamber, isdescribed in commonly assigned U.S. Ser. No. 10/032,284, entitled “GasDelivery Apparatus and Method for Atomic Layer Deposition,” filed Dec.21, 2001, and issued as U.S. Pat. No. 6,916,398, and U.S. Ser. No.10/281,079, entitled “Gas Delivery Apparatus for Atomic LayerDeposition,” filed Oct. 25, 2002, and published as U.S. Pub. No.2003-0121608, which are both incorporated herein in their entirety byreference. In one embodiment, a plasma-enhanced atomic layer deposition(PE-ALD) process is used to deposit tantalum-containing materials, suchas TAIMATA. A chamber and process to perform PE-ALD is further describedin commonly assigned U.S. patent application Ser. No. 10/197,940,entitled “Apparatus and Method for Plasma Assisted Deposition,” filedJul. 16, 2002, and issued as U.S. Pat. No. 6,998,014, which isincorporated herein in its entirety by reference. A detailed descriptionfor a vaporizer or an ampoule to pre-heat precursors, such as TAIMATA,is described in commonly assigned U.S. Ser. No. 10/198,727, filed Jul.17, 2002, and published as U.S. Pub. No. 2004-0013577, and U.S. Ser. No.10/208,305, filed Jul. 29, 2002, and issued as U.S. Pat. No. 6,915,592,which are both incorporated herein in their entirety by reference. Adetailed description for a system to deliver the precursors, such asTAIMATA, to process chamber is described in commonly assigned U.S. Ser.No. 10/197,683, entitled “Method and Apparatus for Gas TemperatureControl in a Semiconductor Processing System,” filed Jul. 17, 2002, andissued as U.S. Pat. No. 6,955,211, and U.S. Ser. No. 10/700,328,entitled “Precursor Delivery System with Rate Control,” filed Nov. 3,2003, and published as U.S. Pub. No. 2005-0095859, which are bothincorporated herein in their entirety by reference.

EXAMPLES

The following hypothetical Examples 1-6 demonstrate some interconnectapplication by deposition processes for tantalum-containing materials,such as tantalum nitride or tantalum silicon nitride described herein.

Example 1

A tantalum-containing material is deposited on a substrate surfacecontaining a dielectric material by an ALD process using TAIMATA asdescribed herein to a thickness in a range from about 5 Å to about 30 Å,preferably about 20 Å. Copper metal is deposited on thetantalum-containing material, such as by a PVD process to a thickness ina range from about 200 Å to about 1,500 Å, preferably about 500 Å.Subsequently, the copper layer may be exposed to an electrochemicalpolishing (ECP) process.

Example 2

A tantalum-containing material is deposited on a substrate surfacecontaining a dielectric material by an ALD process using TAIMATA asdescribed herein to a thickness in a range from about 5 Å to about 50 Å,preferably about 20 Å. Tantalum metal is deposited on thetantalum-containing material by a PVD process or by an ALD process usingTAIMATA described herein to a thickness in a range from about 5 Å toabout 75 Å, preferably about 25 Å. The substrate is exposed to a plasmaetch process to remove materials from the bottom of the via to a depthin a range from about 5 Å to about 100 Å, preferably about 50 Å. Next, atantalum metal is deposited by a PVD process or by an ALD process usingTAIMATA described herein to a thickness in a range from about 5 Å toabout 75 Å, preferably about 25 Å. Copper metal is then deposited on thetantalum metal, such as by a PVD process to a thickness in a range fromabout 200 Å to about 1,500 Å, preferably about 500 Å. Subsequently, thecopper layer may be exposed to an ECP process.

Example 3

A tantalum-containing material is deposited on a substrate surfacecontaining a dielectric material by an ALD process using TAIMATA asdescribed herein to a thickness in a range from about 5 Å to about 50 Å,preferably about 20 Å. The substrate is exposed to a plasma etch processto remove materials from the bottom of the via to a depth in a rangefrom about 5 Å to about 75 Å, preferably about 20 Å. Next, a tantalummetal is deposited by a PVD process or by an ALD process using TAIMATAas described herein to a thickness in a range from about 5 Å to about 75Å,preferably about 25 Å. Copper metal is then deposited on the tantalummetal, such as by a PVD process to a thickness in a range from about 200Å to about 1,500 Å, preferably about 500 Å. Subsequently, the copperlayer may be exposed to an ECP process.

Example 4

A tantalum-containing material is deposited on a substrate surfacecontaining a dielectric material by an ALD process using TAIMATA asdescribed herein to a thickness in a range from about 5 Å to about 50 Å,preferably about 20 Å. Ruthenium metal is deposited on thetantalum-containing material by an ALD process to a thickness in a rangefrom about 5 Å to about 75 Å, preferably about 25 Å. The substrate isexposed to a plasma etch process to remove materials from the bottom ofthe via to a depth in a range from about 5 Å to about 100 Å, preferablyabout 50 Å. Next, a ruthenium metal is deposited by an ALD process to athickness in a range from about 5 Å to about 75 Å, preferably about 25Å. Copper metal is then deposited on the ruthenium metal, such as by aPVD process to a thickness in a range from about 200 Å to about 1,500 Å,preferably about 500 Å. Subsequently, the copper layer may be exposed toan ECP process.

Example 5

A tantalum-containing material is deposited on a substrate surfacecontaining a dielectric material by an ALD process using TAIMATA asdescribed herein to a thickness in a range from about 5 Å to about 50Å,preferably about 20 Å. Ruthenium metal is deposited on thetantalum-containing material by an ALD process to a thickness in a rangefrom about 5 Å to about 75 Å, preferably about 40 Å. The substrate isexposed to a plasma etch process to remove materials from the bottom ofthe via to a depth in a range from about 5 Å to about 100 Å, preferablyabout 50 Å. Next, a ruthenium metal is deposited by an ALD process to athickness in a range from about 5 Å to about 75 Å,preferably about 40 Å.Copper metal is then deposited on the ruthenium metal, such as by a PVDprocess to a thickness in a range from about 200 Å to about 1,500 Å,preferably about 500 Å. Subsequently, the copper layer may be exposed toan ECP process.

Example 6

A tantalum-containing material is deposited on a substrate surfacecontaining a dielectric material by an ALD process using TAIMATA asdescribed herein to a thickness in a range from about 5 Å to about 50 Å,preferably about 20 Å. Ruthenium metal is deposited on thetantalum-containing material by an ALD process to a thickness in a rangefrom about 5 Å to about 75 Å, preferably about 40 Å. Copper metal isthen deposited on the substrate, such as by a PVD process to a thicknessin a range from about 200 Å to about 1,500 Å, preferably about 500 Å.Subsequently, the copper layer may be exposed to an ECP process.

In other examples, metal gate applications for tantalum-containingmaterials may be deposited by ALD processes described herein. The ALDprocesses preferably utilize TAIMATA as a tantalum-containing precursor.The gate layer may contain a gate material such as silicon oxynitride,hafnium oxide, aluminum oxide or combinations thereof. A tantalumnitride or a tantalum silicon nitride layer is deposited on the gatelayer by an atomic layer deposition process described herein. Generally,the tantalum-containing material is deposited on a gate layer with athickness in a range from about 20 Å to about 200 Å, preferably about 40Å. Subsequently, a metal-containing layer is deposited on thetantalum-containing layer. Metal-containing layers may contain titanium,titanium nitride, tungsten, tantalum, ruthenium or combinations thereofand are deposited by CVD, ALD, PVD, electroplating or electrolessplating processes. In one example, the metal-containing layer istitanium nitride deposited by a CVD process, an ALD process or a PVDprocess. In another example, the metal-containing layer is tungstendeposited by a CVD process. In another example, the metal-containinglayer is tantalum deposited by a PVD process or an ALD process usingTAIMATA as described herein. In another example, the metal-containinglayer is ruthenium deposited by an ALD process.

Although the invention has been described in terms of specificembodiments, one skilled in the art will recognize that various changesto the reaction conditions, e.g., temperature, pressure, film thicknessand the like can be substituted and are meant to be included herein andsequence of gases being deposited. For example, sequential depositionprocess may have different initial sequence. The initial sequence mayinclude exposing the substrate to the nitrogen-containing gas before thetantalum-containing gas is introduced into the processing chamber. Inaddition, the tantalum nitride layer may be employed for other featuresof circuits in addition to functioning as a diffusion barrier forcontacts. Therefore, the scope of the invention should not be based uponthe foregoing description. Rather, the scope of the invention should bedetermined based upon the claims recited herein, including the fullscope of equivalents thereof.

While the foregoing is directed to embodiments of the invention, otherand further embodiments of the invention may be devised withoutdeparting from the basic scope thereof, and the scope thereof isdetermined by the claims that follow.

1. A method for forming a tantalum-containing material on a substratesurface, comprising: heating a tantalum precursor comprising TAIMATA toa predetermined temperature to form a tantalum-containing gas; flowingthe tantalum-containing gas into a process chamber containing asubstrate therein; adsorbing the tantalum-containing gas on thesubstrate to form a tantalum-containing precursor layer; purging theprocess chamber with a purge gas; flowing at least one secondaryelement-containing gas into the process chamber; reacting the at leastone secondary element-containing gas with the tantalum-containingprecursor layer to form a tantalum barrier layer on the substrate; andpurging the process chamber with the purge gas.
 2. The method of claim1, wherein the predetermined temperature of the tantalum precursor iswithin a range from about 50° C. to about 80° C.
 3. The method of claim2, wherein the substrate is heated to a temperature within a range fromabout 250° C. to about 400° C.
 4. The method of claim 1, wherein the atleast one secondary element-containing gas comprises a reagent selectedfrom the group consisting of a nitrogen precursor, silicon precursor, aboron precursor, a phosphorous precursor, and combinations thereof. 5.The method of claim 4, wherein a nitrogen precursor is selected from thegroup consisting of ammonia, atomic nitrogen, hydrazine,methylhydrazine, dimethylhydrazine, derivatives thereof, andcombinations thereof.
 6. The method of claim 4, wherein a siliconprecursor is selected from the group consisting of silane, disilane,methylsilane, hexamethyldisilane, tetrachlorosilane, hexachlorodisilane, derivatives thereof, and combinations thereof.
 7. Themethod of claim 4, wherein the tantalum barrier layer is formed having athickness within a range from about 10 Å to about 30 Å.
 8. The method ofclaim 7, wherein a metal layer is deposited on the tantalum barrierlayer, and the metal layer comprises a metal selected from the groupconsisting of copper, tungsten, aluminum, tantalum, titanium, rutheniumalloys thereof, combinations thereof.
 9. A method for forming atantalum-containing material on a substrate surface, comprising: forminga tantalum-containing gas by heating a liquid TAIMATA precursorcontained within a vaporizer to a predetermined temperature, whileflowing a carrier gas through the vaporizer; exposing a substrate withina process chamber to an atomic layer deposition process comprising apulse of the tantalum-containing gas, a pulse of a nitrogen-containinggas, and a pulse of a silicon-containing gas; and forming a tantalumbarrier layer having a predetermined thickness by repeating the atomiclayer deposition process.
 10. The method of claim 9, wherein thepredetermined temperature of the liquid TAIMATA precursor is within arange from about 50° C. to about 80° C.
 11. The method of claim 10,wherein the substrate is heated to a temperature within a range fromabout 250° C. to about 400° C.
 12. The method of claim 9, wherein thenitrogen-containing gas comprises a nitrogen precursor selected from thegroup consisting of ammonia, atomic nitrogen, hydrazine,methylhydrazine, dimethylhydrazine, derivatives thereof, andcombinations thereof.
 13. The method of claim 12, wherein thesilicon-containing gas comprises a silicon precursor selected from thegroup consisting of silane, disilane, methylsilane, hexamethyldisilane,tetrachlorosilane, hexachlorodisilane, derivatives thereof, andcombinations thereof.
 14. The method of claim 13, wherein thepredetermined thickness of the tantalum barrier layer is within a rangefrom about 10 Å to about 30 Å.
 15. The method of claim 14, wherein ametal layer is deposited on the tantalum barrier layer, and the metallayer comprises a metal selected from the group consisting of copper,tungsten, aluminum, tantalum, titanium, ruthenium alloys thereof, andcombinations thereof.
 16. A method for forming a device by depositing atantalum-containing material on a substrate surface, comprising:exposing a substrate within a process chamber sequentially to a pulse ofa tantalum-containing gas comprising TAIMATA and to a pulse of a processgas comprising at least one secondary precursor; depositing atantalum-containing film on the substrate; repeating the exposing stepuntil the tantalum-containing film is deposited having a predeterminedthickness; and depositing a metal layer on the tantalum-containing film.17. The method of claim 16, wherein the tantalum-containing gas isheated to a predetermined temperature within a range from about 50° C.to about 80° C.
 18. The method of claim 17, wherein the substrate isheated to a temperature within a range from about 250° C. to about 40°C.
 19. The method of claim 17, wherein the at least one secondaryprecursor is selected from the group consisting of a nitrogen precursor,silicon precursor, a boron precursor, a phosphorous precursor, andcombinations thereof.
 20. The method of claim 19, wherein a nitrogenprecursor is selected from the group consisting of ammonia, atomicnitrogen, hydrazine, methylhydrazine, dimethylhydrazine, derivativesthereof, and combinations thereof.
 21. The method of claim 19, wherein asilicon precursor is selected from the group consisting of silane,disilane, methylsilane, hexamethyldisilane, tetrachlorosilane,hexachlorodisilane, derivatives thereof, and combinations thereof. 22.The method of claim 19, wherein the predetermined thickness of thetantalum-containing film is within a range from about 10 Å to about 30Å.
 23. The method of claim 22, wherein the tantalum-containing filmcomprises a material selected from the group consisting of tantalum,tantalum nitride, tantalum silicon nitride, tantalum boron nitride,tantalum phosphorous nitride, tantalum oxynitride, tantalum silicide,derivatives thereof, and combinations thereof.
 24. The method of claim23, wherein the metal layer comprises a metal selected from the groupconsisting of copper, tungsten, aluminum, tantalum titanium, ruthenium,alloys thereof, and combinations thereof.
 25. A method for depositing atantalum-containing gate material on a substrate surface, comprising:exposing a substrate to an ALD process cycle to form atantalum-containing material thereon, wherein the ALD process cyclecomprises a pulse of a tantalum-containing gas comprising TAIMATA, apulse of a nitrogen precursor, and a pulse of a third precursor selectedfrom the group consisting of a silicon precursor, a boron precursor, aphosphorous precursor, and combinations thereof; and repeating the ALDprocess cycle until the tantalum-containing material is deposited on thesubstrate having a predetermined thickness.
 26. The method of claim 25,wherein a metal contact layer is deposited on the tantalum-containingmaterial.
 27. The method of claim 25, wherein the predeterminedthickness of the tantalum-containing material is within a range fromabout 40 Å to about 200 Å.
 28. The method of claim 27, wherein thetantalum-containing material comprises a material selected from thegroup consisting of tantalum silicon nitride, tantalum boron nitride,tantalum phosphorous nitride, derivatives thereof, and combinationsthereof.
 29. The method of claim 28, wherein the tantalum-containingmaterial comprises tantalum silicon nitride, and a silicon precursorcomprises a precursor selected from the group consisting of silane,disilane, and methylsilane.
 30. The method of claim 28, wherein thetantalum-containing material comprises tantalum boron nitride, and aboron precursor comprises diborane.
 31. The method of claim 28, whereinthe tantalum-containing material comprises tantalum phosphorous nitride,and a phosphorous precursor comprises phosphine.